The relationship between maltreatment victimisation and sexual and violent offending: differences between adolescent offenders with and without intellectual disability.

BACKGROUND: Juveniles with intellectual disabilities (ID) are more often victims of maltreatment and more often perpetrators of abuse than juveniles without ID. Because previous research on the relationship between maltreatment victimisation and subsequent offending behaviour was primarily performed in non-disabled samples, the present study aimed to examine differences between juvenile offenders with and without ID in the relationship between maltreatment victimisation and sexual and violent offending.

METHOD: The sample consisted of juvenile offenders with ID (n = 102) and without ID (n = 526) who appeared before the courts for a criminal act and for whom the Washington State Juvenile Court Assessment (WSJCA) was completed. Pearson correlation coefficients were calculated to determine the strength of the relationship between maltreatment and offending, Fisher's z tests were calculated to assess the significance of the differences between the two groups in the strength of the correlations, and multiple logistic regression analyses were performed to examine the unique contribution of maltreatment victimisation to the prediction of violent and sexual offending.

RESULTS: Seventy per cent of the juvenile offenders with ID and 42% of the juvenile offenders without ID had experienced abuse and/or neglect. Both sexual and violent offending were more common in juvenile offenders with ID than in juvenile offenders without ID. Moreover, the relationship between different forms of maltreatment and sexual offending was stronger in juvenile offenders with ID than in juvenile offenders without ID.

CONCLUSIONS: Given the high rates of abuse and neglect victimisation and the strength of the association between victimisation and sexual offending, especially in juvenile offenders with ID, treatment should focus on potential trauma and other problems associated with the abuse.